Method of lead lining tanks



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METHOD OF LEAD LINING TANKS Filed Oct. 15, 1963 e Sheets-Sheet e I I I I I I I I I I I I I I I NVEN TOR PICHE M 5 WM I l I I I I PMAND 5 United States Patent M 3,339,266 METHOD OF LEAD LINING TANKS Armand S. Piche, Montreal, Quebec, Canada, assignor to American Smelting and Refining Company, New York, N.Y., a corporation of New Jersey Filed Oct. 15, 1963, Ser. No. 316,328 3 Claims. (Cl. 29-469) The invention relates to linings for containers, and more particularly to lead linings for electrolytic cells, and to a method and apparatus for lining the cells.

In the electrodeposition of metals such as zinc it is common practise to use a concrete cell with a lead lining to hold the electrolyte, which is mainly sulphuric acid. The sheets forming the vertical walls of the cell are joined by seams formed by welding or burning the lead sheets to connect them at the corners. Lead burning vertical seams is a tedious and time consuming job. Burning horizontal seams is easier and quicker.

According to the present invention, all seams of the lead lining are burned while in horizontal position, regardless of their position in the completed cell, and all seams are accessible from the inside of the lined cell.

According to a preferred form of the present invention, the cell lining comprises a single bottom sheet, a smaller side sheet forming one vertical wall, and a larger U shaped side sheet forming the other three vertical walls. The sheets are connected by welding or burning the seams.

According to a preferred form of the invention, the lead lining is assembled by laying the bottom sheet on the cell bottom, the smaller and larger side wall sheets are pre-assembled around a hollow mandrel, and the seams connecting the smaller and larger side wall sheets are burned from the inside of the mandrel and while in horizontal position. The mandrel and pre-assembled tube of side wall sheets are then lowered into the concrete cell, and the mandrel is removed. Then the horizontal seams joining the four side wall sheets and bottom wall sheet are burned by a man inside the lined cell.

According to a preferred form of the present invention, the assembly of the smaller and larger lead sheets about the mandrel is done in the cab of a crane straddling a row of concrete cells to be lined. Tracks are arranged on either side of the row of cells, and the crane works on the cells in order, being moved from one cell to the next, as the linings are placed in the cells.

According to a preferred form 'of the present invention, the cab has a deck including -a raised horizontal platform on its floor. A hollow aluminum mandrel having side walls corresponding to the side walls of the cell is adapted to rest on the platform in reclining position. The lower wall of the reclining mandrel has access openings adjacent the open spaces at the ends of the deck. The deck has a bending "blade at either end. The deck has bearings at either end for supporting a brake blade.

According to a preferred form of the present invention, to pre-assemble the lead lining for the side walls, the smaller sheet is laid on the deck, and its end margins are bent downwardly against the bending blades. The mandrel is then placed on top of the smaller sheet in reclined position, and the larger lead sheet is wrapped around the top side and vertical sides of the reclining mandrel. The brake blade is rotated to wrap the depending margins of the larger sheet around the lower rounded corners of the mandrel to positions adjacent the access spaces, after which the bending blades are rotated to raise the margins of the smaller sheet against the margins of the larger sheet. A workman then enters the inside of the mandrel and connects the adjoining horizontal margins of the smaller and larger sheets by burning them through the access spaces.

Other objects and features of the invention will be 3,339,233 Patented Sept. 5, 1967 more apparent from the following description when considered with the accompanying drawings in which:

FIG. 1 illustrates somewhat diagrammatically the apparatus used for forming the lead lining and for installing it in the concrete cell;

FIG. 2 is a perspective of the liner with the parts in position they assume in the concrete cell;

FIG. 3 is a perspective of the mandrel, about which the vertical lining sheets are pre-assembled;

FIG. 4 is a plan view of the deck on which the lining is pro-assembled;

FIG. 5 is an elevation of the deck illustrating the mandrel in position during pre-assembly;

FIG. 6 is an end view of the deck, taken on the line 6-6 of FIG. 4, and illustrating the bending blade and braking blade;

FIG. 7 is an enlarged fragmentary elevation of one end of the deck showing the smaller lead sheet in position during pre-assenrbly.

FIG. 8 is an elevation corresponding to FIG. 7, but showing the mandrel and braking blade in position;

FIG. 9 is a view corresponding to FIGS. 7 and 8, showing the bending blade in upper position and the braking blade removed;

FIGS. 1014 are diagrams illustrating the several stages of the pre-assembly of the lining on the mandrel.

FIG. 15 is a diagrammatic view illustrating the mandrel Wit-h pre-assembled lining wrapped around it, preparatory to lifting from reclining position to upright position for lowering into the cell;

FIG. 16 is a diagrammatic perspective showing the mandrel and pre-assembled lining tube about to be lowered into the cell;

FIG. 17 is a diagrammatic section showing how the upper and lower margins of the pre-assembled lining tube are folded around the upper and lower ends of the mandrel;

FIG. 18 is a section through a completed cell with the lining in place.

In the following description and in the claims, various details will be identified by specific names, for convenience, but they are intended to be as generic in their application as the art will permit.

Like reference characters denote like parts in the several figures of the drawings.

In the accompanying drawings and description forming part of this specification, certain specific disclosure of the invention is made for purposes of explanation, it will be understood that the details may be modified in various respects Without departure from the broad aspect of the invention.

Referring to FIGS. 1 and 2, the lining in position in the electrolytic cell will first be described. The cell 10 may be of conventional concrete construction, having a bottom wall, upstanding side walls, and upstanding end walls. The end walls are narrower than the side walls.

The lead lining comprises a bottom sheet 11, a smaller sheet 12 for a single side wall, and a larger sheet 13 for the other side and two end walls. The construction and position of the seams connecting the several sheets together is especially important.

The ends of the larger side sheet 13 have flaps 18 which overlie the smaller side sheet 12 on the inside of the cell. The vertical seams 14 are burned at the edges of the flaps 18. The lower margins of the side and end wall sheets are turned inwardly to form bottom flaps 19 which overlie the bottom sheet 11. The edges of these bottom flaps 19 are burned at seams 15 to the bottom sheet 11. Thus, all seams are exposed to and accessible from, the inside of the lined cell.

The apparatus for forming the lead lining, and for installing it in the concrete cell, will now be described.

As shown in FIG. 1, the apparatus comprises a travelling crane 21 straddling a row of concrete cells which are to be lead lined. The cells are shown resting on the ground adjacent the electrolytic plant and are not in working position in the plant. After they are lined, the cells are carried to working position in the electrolytic plant. The crane has a cab which is large enough to be used as a workroom. The crane moves on tracks 22 on either side of the cell row, from cell to cell.

The workroom has a deck 25 including a raised plywood platform 46 with an opening 26 in the floor alongside the deck. The workroom contains an aluminum mandrel 27 and a hoist 28. The hoist is used for lowering the mandrel carrying the lead side and end sheets into the cell through the opening in the workroom floor, and for raising the mandrel back into the workroom after the lead sheets have ben removed. The hoist 28 is used also for raising the rolls of lead sheeting, indicated by 29 and 30,

into the workroom, and for general hoisting purposes.

Refrring now to FIG. 3, the aluminum mandrel 27 will now be described. It will be described as standing in upright position; this is the position it assumes when it is lowered into the concrete cell. While the lead lining tube is being pre-assembled, the mandrel 27 is in reclined position, lying on its side, as explained below.

The mandrel 27 has a top or hoisting end 43 and an open bottom or entry end 44. It comprises a framework having end walls 33 and side walls 34, 35 corresponding to the lining end and side walls. The hoisting end has a top beam having loop 36 to which the hook of the hoist 28 will be attached for lowering the mandrel into the cell. The mandrel has positioning holes 37 for registration with holes 38 in the plywood platform 46, as explained below. The framework has four rounded vertical corners 39, 40 and four rounded lower edges 41.

All four vertical walls 33, 34, 35 are covered with sheet metal except for the open access spaces near the ends of side 34 which will rest on the small sheet 12 on platform 46 (FIG. 8) during pre-assembly. All four vertical walls 3335 and vertical rounded corners 39, 40 are tapered slightly, converging from top to bottom, to facilitate separation of the mandrel from the partially assembled lead lining, and to fit the lining into the concrete cell.

Referring now to FIGS. 4-9, the deck 25 will now be described. Resting upon the floor of the cage is a plywood platform 46 raised above the floor a distance of six inches or so. This platform is perfectly fiat and supports the smaller lead sheet 12 forming the single side Wall lining of the cell. It has positioning holes 38 for registration with holes 37 on the mandrel 27.

As shown in FIGS. 4 and 5, at each end of the plywood deck 25 is a bending blade 50 and a braking blade 51. The bending blades 50 are for supporting and bending up the margins 52 of the smaller sheet 12 (FIGS. 7, 8 and 9), and the braking blades 51 are for bending and braking the flaps 18 of the larger sheet 13 (FIGS. 8 and 9).

The bending blade 50 comprises a blade member connected to the platform 46 by a series of hinges 53. The bending blade 50 extends all the way across the platform 46 and is tapered as indicated by 54 in FIG. 4. It has one or more sockets 55 to receive a handle for rotating the blade.

The braking blade 51 and its mountings will now be described. The blade member comprises a pair of angle irons 58 secured face to face (FIG. 8). The blade member has sockets 59 for receiving an operating handle. The blade member has an ear 60 at each end supporting a journal 61 provided with a collar 62 (FIG. 6).

The braking blade 51 is supported on the floor by a fixed post 63 and a hinged post 64 having hinge 65. Each post has a socket with an open top, providing bearings 66 (FIG. 7) for the journals of the blade. The post 64 is hinged to permit it to fold down against the floor when lifting the mandrel 27 from the deck to lower it into the cell, as explained below.

A fixed post 63 and hinged post 64 is disposed at either end of the deck. If desired, the same braking blade 51 may be used for each end. After bending one end of the larger sheet 13, the braking blade 51 may be simply 'lifted out of its bearings 66 and transferred to the bearings at the other end of the deck where the other end of the larger lead sheet may be bent.

The bearings 66 and journals 61 are laid out on an axis 67 (FIG. 4) which is parallel to the taper 54 of the bending blade 50, but the braking blade 51 itself is not tapered. The rounded mandrel corner 40 has a circular cylindrical surface whose axis coincides with the blade axis 67.

Referring now also to FIGS. 10-44, the manner of using the equipment will now be explained. The smaller lead sheet 12, which forms the single side wall, is first placed on the raised platform 46. The sheet 12 is somewhat narrower than the plywood platform (FIGS. 4 and 6) but extends beyond the ends of the platform. The sheet 12 is wider than the height of the mandrel. The bending blades 50 are in upper position, and the end margins 52 of the smaller sheet 12 and blades 50 are folded down by hand into the spaces at the ends of the deck.

The mandrel 27 is then placed in reclining position on its side with the access spaces 45 facing downwardly, resting on top of the lead sheet 12 on the raised platform 46. Positioning pins 72 (FIG. 6) are inserted through the positioning holes 37, 38 of mandrel and deck to hold the mandrel in proper position. The taper on the mandrel rounded corners 40 corresponds to the taper of the axis 67 of the braking blades 51 and the taper of the bending blades 50.

The longer lead sheet 13 is then placed on the upper side of the reclining mandrel 27 with its ends hanging over the ends of the mandrel, as shown in FIG. 12. The brake blade 51 is then placed in its bearings 66, and the handle placed in its socket 59. This positions the depending ends of the longer sheet 13 inbetween the rounded lower corner 40 of the mandrel and the braking blade 51 (FIGS. 8 and 12).

The braking blade 51 is then rotated from vertical to horizontal position by operating the handle (FIG. 12 to FIG. 13). This folds the margin 18 of the larger lead sheet 13 under the rounded lower corner 40 of the mandrel.

The braking blade 51 is then removed and positioned in its bearings at the other end of the raised deck, and the other end of the larger lead sheet 13 is bent in a manner similar to that just described. The bending blades 50 are then raised to bring up the margins 52 of the smaller lead sheet 12 under the margins 18 of the larger sheet 13.

The seams 14 at both ends of the larger sheet 13 are now in position to be burned. These seams are burned by a man inside the mandrel 27, who operates through the access spaces 45. The seams 14 are in horizontal position, which facilitates burning.

The two lead sheets 12, 13 are now joined together forming a tube-like structure wrapped around the mandrel 27, which is still in reclining position. One free margin 70 of the tube projects beyond the top of the mandrel, and the other free margin 19 of the tube projects beyond the rounded bottom edges 41 of the mandrel.

As shown in FIG. 15, with the mandrel 27 lying on its side, the projecting margins 19 on three sides, i.e., on the upstanding and top sides with respect to its reclining position, and top margin 70, are in convenient position for a workman to dress the margins and turn them in.

These projecting margins 19 are then turned in about the three rounded edges 41 of the open bottom 44 of the right position by engaging the hook of the hoist 28 with the lifting loop 36. As a part of the raising operation, the mandrel 27 is tilted around the fourth rounded edge in contact with the platform 46 to the dotted line position in FIG. 15. This automatically bends the fourth margin 19 inward to correspond with the flaps 19 of the other three sides. The second upper margin 70 on the long side is then turned in about the long upper edge of the mandrel to hold the pre-assembled lining tube from slipping off when the mandrel is raised to upright position for lowering into the cell.

The mandrel is then raised from the deck into upright position and then lowered through the opening in the floor of the cab into the cell 10. See FIGS. 1, 16 and 17.

Before lowering the mandrel 27 with mounted lead sheeting tube into the cell, the bottom lead sheet 11 is placed in the bottom of the cell 10. This sheet fits the bottom wall of the cell. After lowering the mandrel into the cell, the upper margins 70 of the lead sheet are unfolded from the mandrel 27 and the mandrel is lifted out of the cell, leaving the pre-assembled lead lining tube in position in the cell.

The flaps 19 of the side wall sheets now overlie the bottom sheet 11 in the :cell. The bottom seams 15 are in horizontal position and are burned by a man in the cell.

The upper margins 70 of the side sheets are then bent over the top edges of the concrete cell and secured in position in any desired manner. The crane 21 is then moved to a position over the next concrete cell, and the lining operation above described is repeated.

The invention has many advantages. The lead lining has all inside seams when installed in the cell, which makes it easier to repair .a seam and also makes a better appearance-in contrast to an outside seam which is inaccessible after the lining is placed in the cell.

A further advantage is that all seams, whether horizontal or vertical in the cell, are burned while the seam is in horizontal position. Horizontal burning is much faster and more reliable than vertical burning.

The use of the hollow mandrel with access slots enables the workman to burn the vertical seams while in horizontal position and to place them on the inside of the cell lining. The plywood platform and bending blades and braking blades enables the lining to be formed and dressed in a most expeditious manner.

The projecting margins of the tube-like lining, While resting on the deck, are exposed and in position for convenient bending inward, and the tilting of the mandrel from reclining position to upright position, around one lower rounded edge, bends the fourth margin inwardly.

While certain novel features of the invention have been disclosed herein, and are pointed out in the annexed claims, it will be understood that, in accordance with the doctrine of equivalents, various omissions, substitutions and changes may be made by those skilled in the art without departing from the spirit of the invention.

What is claimed is: 1. The method of lining with lead sheeting an electrolytic cell having a bottom wall and upstanding side walls, said method comprising laying a bottom lead sheet on the bottom wall of said cell, forming lead sheeting into a tube having at least one seam extending lengthwise of the tube, lead burning the seam from the inside of the tube while the seam is in horizontal position, bending inwardly an end margin of the tube to form a flap, placing the tube in the cell, and lead burning a seam from the inside of the tube to connect the flap with the bottom sheet.

2. The method of lining a cell with sheet lead, said lining comprising a bottom wall and four upstanding Walls, said lining having vertical seams connecting said upstanding walls and horizontal seams connecting said bottom Wall and upstanding walls, said method comprising placing the bottom sheet on the bottom wall of the cell, assembling a plurality of sheets around a hollow mandrel with adjoining margins in horizontal position, burning said margins to form seams while in horizontal position to form a tube, placing the tube in the cell, and then burning the seams joining the tube and bottom Wall.

3. The method of making and positioning a lead lining in a cell, said cell having a bottom wall and upstanding side walls, said method comprising placing a first lead sheet on the bottom of the cell, said sheet substantially fitting said bottom and lying fiat against the bottom, forming the side wall lining by fitting a plurality of sheets around the sides of a hollow mandrel with their adjacent margins overlapping, and with the mandrel in reclining position, said mandrel having access openings in its lower side, burning seams from the inside of said mandrel through said access openings, bending the edges of said sheets in around the ends of the mandrel, moving the mandrel from its reclining position to its upright position, lowering the mandrel with its wrapped-around lining into the cell, removing the mandrel from the lining, and burning the inturned margins of the side wall lining to said first lead sheet.

References Cited UNITED STATES PATENTS 719,778 2/1903 Ford 206-2 907,552 12/1908 Zuern 2062 942,990 12/1909 Willard 2062 1,152,783 9/ 1915 Borsari-Fischer 2062 1,3 58,869 11/ 1920 Norris. 1,601,927 10/ 1926 Tobey. 2,108,409 2/ 1938 Peron 29-480 2,163,619 6/1939 Murch. 2,608,887 9/1952 Sowter. 2,755,839 7/1956 Garrock et a1 15325 2,766,517 10/1956 Ericson 29480 3,040,428 6/1962 Sundholm 29475 3,109,476 1l/1963 Giordano 153-2l JOHN F. CAMPBELL, Primary Examiner. G. O. RALSTON, Examiner.

I. L. CLINE, J. M. CASKIE, Assistant Examiners. 

1. THE METHOD OF LINING WITH LEAD SHEETING AN ELECTROLYTIC CELL HAVING A BOTOM WALL AND UPSTANDING SIDE WALLS, SAID METHOD COMPRISING LAYING A BOTTOM LEAD SHEET ON THE BOTTOM WALL OF SAID CELL, FORMING LEAD SHEETING INTO A TUBE HAVING AT LEAST ONE SEAM EXTENDING LENGTHWISE OF THE TUBE, LEAD BURNING THE SEAM FROM THE INSIDE OF THE TUBE WHILE THE SEAM IS IN HORIZONTAL POSITION, BENDING INWARDLY AN END MARGIN OF THE TUBE TO FORM A FLAP, PLACING THE TUBE IN THE CELL, AND LEAD BURNING A SEAM FROM THE INSIDE OF THE TUBE TO CONNECT THE FLAP WITH THE BOTTOM SHEET. 